Apparatus for forming closing heads at rivets

ABSTRACT

THERE IS DISCLOSED AN APPARATUS FOR FORMING CLOSING HEADS AT RIVET WITH THE AID OF A RIVET SET OR ANVIL WHICH CARRIES OUT LOOP-LIKE REVOLVING MOVEMENTS. ACCORDING TO THE INVENTION, THE RIVET SET IS SUPPORTED IN A CRANK-LIKE ELEMENT WHICH COOPERATES WITH A DRIVE SHAFT, THE AXIS OF ROTATION OF SAID CRANK-LIKE ELEMENT BEING INCLUDED WITH RESPECT TO THE AXIS OF ROTATION OF THE DRIVE SHAFT. FURTHER, THE CRANK AXIS OF THE CRANK-LIKE ELEMENT IN ONE EXTREME POSITION AS LEAST APPROXIMATELY COINCIDES WITH THE AXIS OF THE DRIVE SHAFT AND IN THE OTHER EXTREME POSITION SUCH CRANK AXIS INTERSECTS THE AXIS OF THE DRIVE SHAFT AT THE REGION OF THE RIVET.

Nov. 16, 1971 RAMSElER 3,620,060

APPARATUS FOR' FORMING CLOSING HEADS AT RIVETS Filed April 5, 1970 3 Sheets-Shoot l Fig. 1 Fig. 2

INVENTOR pH at P/amaE/ER ATTORNEY NOV. 16, 1971 RAMSElER 3,620,060

APPARATUS FOR FORMING CLOSING HEADS AT RIVETS Filed April 5, 1970 3 Sheets-Shoot 1.

R El

INVENTOR BY WW 60. M

ATTORNEY P. RAMSEIER 3,620,060

APPARATUS FOR FORMING CLOSING HEADS AT RIVETS Nov. 16, 1971 3 Sheets-Sheet 5 Filed April 5, 1970 Fig. 4

INVENTOR p? 414 P4 MGE/E/Q BY 60W 60. M

ATTORNEY United States Patent O HEADS 9 Claims ABSTRACT OF THE DISCLOSURE There is disclosed an apparatus for forming closing heads at rivets with the aid of a rivet set or anvil which carries out loop-like revolving movements. According to the invention, the rivet set is supported in a crank-like element which cooperates with a drive shaft, the axis of rotation of said crank-like element being inclined with respect to the axis of rotation of the drive shaft. Further, the crank axis of the crank-like element in one extreme position as least approximately coincides with the axis of the drive shaft and in the other extreme position such crank axis intersects the axis of the drive shaft at the region of the rivet.

BACKGROUND OF THE INVENTION The present invention relates to a new and improved apparatus for form-ing closing heads at rivets with the aid of a rivet set or anvil which performs loop-like revolving movements.

Riveting machines are known to the art wherein the rivet set supports means traces a hypocycloidal path, the movement being generated by hypocycloidal gearing. The uper end of the rivet set support is in the form of a spherical segment-like member and bears against a ball cup or socket which takes up the rivet forming pressure. However, because of the frictional forces which occur these components are quite subject to wear. Additionally, the lateral forces which appear at the rivet set or anvil can only be taken up to a limited extent, since otherwise the rivet set support will tend to periodically raise away from the ball cup or socket.

SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide an improved apparatus for forming closing heads at rivets which effectively overcomes the aforementioned drawbacks of the prior art constructions.

Another, more specific object of the present invention relates to an improved apparatus for forming closing heads at rivets which overcomes the aforementioned drawbacks of the prior art while dispensing with the use of spherical segments and ball sockets.

Yet another significant object of the present invention relates to an improved apparatus for reliably forming closing heads at rivets in an extremely simple and efficient manner.

Now, in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the apparatus of the invention contemplates supporting the rivet set or anvil in a crank-like elements which cooperates with the drive shaft, the axis of rotation of the crank-like element being inclined with respect to the axis of rotation of the drive shaft. Furthermore, the crank axis of the crank-like ele ment in one extreme position at least approximately coincides with the axis of rotation of the drive shaft and in the other extreme position intersects the axis of rotation of the drive shaft at the region of the rivet.

By virtue of the aforementioned construction it is now ice possible to reduce the friction appearing at the riveting apparatus, and furthermore, it is also advantageously possible to use conventional roller bearings for supporting the rank-like element.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood and objects other than those set forth above will become apparent, when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:

FIG. 1 is a schematic representation of a preferred embodiment of the inventive apparatus showing the components in one extreme position;

FIG. 2 is a schematic representation of the inventive apparatus, with the components depicted in the other extreme or terminal position;

FIG. 3 is a sectional view through an embodiment of inventive riveting apparatus; and

FIG. 4 is a sectional view through a further embodiment of inventive riveting apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS escribing now the drawings, in the schematic representations of inventive apparatus shown in FIGS. 1 and 2. the main drive shaft 1 having the drive shaft axis of rota-- tion x is placed into rotation by any suitable motor, which for convenience in illustration has not been shown. The bearings 2 and 3 are rigidly connected with this drive shaft 1, so that these bearings likewise revolve during each rotation of the shaft member 1. A crank-like element 4, 5 is rotatably supported in both of the bearings 2 and 3, as shown. The upper portion 4 of this crank-like element 4, 5 is rotatable about its own axis of rotation y, the latter of which encloses an angle a with respect to the axis of rotation x of the drive shaft 1. The lower portion 5 of the such crank-like element 4, 5 is constructed as the support means for the rivet set or anvil 6 or its support.

The rivet set 6 is secured against rotation about its own axis z. Its axis z forms an angle 5 with respect to the axis of rotation y of the crank-like element 4, 5. In the one extreme position depicted in FIG. 1 the axis z of the rivet set 6, which axis will hereinafter be conveniently referred to as the crank axis z, extends at an angle 'y with respect to the axis of rotation x of the drive shaft 1. This angle 'y is composed of the summation of the angles oc-I-B which are of the same magnitude with respect to one another. The selection of this angle is such that in the other extreme positionin other words in the position shown in FIG. 2the crank axis 2 and the drive shaft axis x extend coaxially or at least approximately coaxially with respect to one another. Additionally, the crank axis 2 should intersect the drive shaft axis x in the extreme position shown in FIG. 1 at the region of the rivet 8, preferably at the closing head to be formed or at the center point of the closing head-spherical segment. It will be observed that in the extreme position depicted in FIG. 1 all three of the aforedescribed axes x, y and z intersect at a point P at the region of the rivet 8, and furthermore, they are disposed in a common plane.

The shaft 1 and the crank-like element 4, 5 are driven with the same or different number of revolutions and the same or opposite direction of rotation. This can be achieved through the provision of an intermediately arranged gearing or, in any event, by providing two drive motors. In so doing, the rivet set or anvil 6 performs a loop-shaped, rosette-like movement, the shape of which can be changed by producing or changing the the difference in the number of revolutions or rotational speed of the aforedescribed rotational components.

Considering now the structural embodiment of invention depicted in FIG. 3, it will be understood that for the transmission of the rotational movement there is provided a hypocycloidal gearing wherein the gear 11) meshes with an internal ring gear 11 of larger diameter and which is fixed against rotation. Depending upon the selected gear teeth ratio, the rivet set 6 traces a predetermined loopshaped path of movement. Furthermore, a radially extending pin member 13 depends laterally from the rivet set support 21 and engages in an opening 14 of a member which is connected with the stationary bushing or sleeve 15, in order to prevent rotation of the rivet set or anvil 6 about its own axis. The rivet set support means 21 is mounted at the drive shaft 12 with the aid of a needle bearing 24 provided at the end of the shaft member 17 of the rivet set support 21.

Continuing, it will be observed that the driven shaft 12, in turn, is rotatably mounted by a pin or journal 22 in the spindle 16. The axial forces are absorbed by ball bearings 18, 19, or suitable pressure bearings. The driven shaft 12corresponding to the crank-like element 4 of FIGS. 1 and 2-is inclined with respect to the drive shaft axis x of the spindle 16, so that therefore both axes x and y form an acute angle with respect to one another. In the illustrated position, the crank axis zcorresponding to the one extreme position depicted in FIG. 2extends coaxially with respect to the drive shaft axis x. Additionally, the conditions mentioned in conjunction with the schematic representation of apparatus of FIGS. 1 and 2, namely with respect to the axes, angle and point of intersection, is likewise valid in this embodiment. By rotating the spindle 16, with the bushing 15 supported against rotation, the smaller diameter gear 10 rolls upon the internal gear ring 11 of the bushing 15, so that the driven shaft 12 traces a hypocycloid. Owing to the rolling-off movement the inclination of the crank axis z continuously changes and therefore also the rivet set 6, so that there results the desired loop-movement for forming or setting the rivet head.

In the embodiment depicted in FIG. 4 the drive occurs by means of epicycloidal gearing. More precisely, it will be understood that a motor driven spindle 26, mounted for rotation about the axis x, is rotatably mounted in the bushing or sleeve member 25 which is rigidly supported aaginst rotation. Within a bore of this spindle 26 there is arranged epicycloidal gearing incorporating the gears 31 and 33. The gear 33 is seated upon a shaft member 32 which can be either stationary or driven. The gear 31 is operatively connected via a shaft 34 with the driving Shaft 27, at the lower end of which there is seated the rivet set 28 or forms together with such a single piece. The position of the components depicted in FIG. 4 corresponds to the positional arrangement shown in FIG. 2, wherein the axes x and z extend coaxially. Also in this embodiment the conditions with respect to axes, angle and point of intersection, as such have been explained in conjunction with the arrangement of FIGS. 1 and 2, also hold true. The support 28 of the rivet set or anvil 6, just as was the case with the embodiment of FIG. 3, is here also secured against rotation about its own axis by means of the radially extending pin member 29. The axial forces acting during the riveting operation upon the shaft member 27 are taken up by a roller bearing seated in the bore of the spindle member 26.

While there is shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims. Accordingly, I claim:

1. An apparatus for forming closing heads at rivets by means of a rivet set performing loop-like revolving movements, comprising a drive shaft rotatable about an axis of rotation ,a rotatable crank-like element for supporting the rivet set and cooperating with said rotatable drive shaft, said rotatable crank-like element having an axis of rotation and a crank axis, said axis of rotation of said cranklike element being inclined with respect to said axis of rotation of said drive shaft, said crank axis assuming two extreme positions, said crank axis in one extreme postion at least approximately coinciding with said axis of rotation of said drive shaft and in the other extreme position intersecting said axis of rotation of said drive shaft at the region of the rivet.

2. An apparatus as defined in claim 1, wherein said axis of rotation of said drive shaft, said axis of rotation of said crank-like element and said crank axis at least approximately intersect at a predetermined point.

3. An apparatus as defined in claim 2, wherein said predetermined point of intersection of the aforementioned three axes is situated at the rivet.

4. An apparatus as defined in claim 1, wherein the angle between the axis of rotation of said drive shaft and the axis of rotation of said crank-like element is equal to the angle between the axis of rotation of said crank-like element and said crank axis.

5. An apparatus as defined in claim 1, wherein said axis of rotation of said drive shaft, said axis of rotation of said crank-like element and said crank axis are disposed in a common plane in both of said extreme positions.

6. An apparatus as defined in claim 1, wherein said drive shaft is provided with a bore, said crank-like element embodying a crank-like driven shaft member mounted at an inclination in said bore, a gear provided for said cranklike driven shaft member, an internal gear ring means secured against rotation and forming together with said gear of said crank-like driven shaft member hypocloidal gearing, said gear meshing with said internal gear ring means, a rivet set support means rotatably mounted at said driven shaft member, and means for securing said rivet set support means against rotation about its own axis.

7. An apparatus as defined in claim 1, wherein said drive shaft includes a bore, epicycloidal gearing for driving said crank-like element disposed in said bore.

8. An apparatus as defined in claim 7, wherein said crank-like element comprises a crank-like driven shaft member mounted at an inclination in said bore, a pinion provided for said crank-like driven shaft member, gear means, said pinion meshing with said gear means and defining said epicycloidal gearing, a rivet set support means provided for said crank-like driven shaft member, and means for securing said rivet set support means against rotation about its own axis.

9. An apparatus as defined in claim 8, wherein said rivet set support means is integrally formed of one piece with said driven shaft member.

References Cited UNITED STATES PATENTS 2,998,839 9/1961 Ingwer 72l26 X 3,117,617 1/1964 Meese 72-126 X 3,173,281 3/1965 Bodmer 72-67 3,440,850 4/1969 Freidrich 72429 X I. SPENCER OVERHOLSER, Primary Examiner J. E. ROETHEL, Assistant Examiner US. Cl. X.R. 72126 

